Senior z/OS Unix & zLinux Integration Engineer

Ensono is an expert technology adviser and managed service provider. As a relentless ally, we accelerate clients’ digital transformation to achieve business outcomes that stand to last. Our dedicated team helps organizations optimize today’s systems across any hybrid environment with services such as consulting, mainframe and application modernization, public cloud migration and cloud-native development. With certified experts in AWS, Azure and Google Cloud and recognized as Microsoft Datacenter Transformation Partner of the Year, Ensono has over 3500+ associates globally and is headquartered in greater Chicago.

Your role: As a Senior z/OS UNIX & zLinux Integration Engineer, you will spearhead efforts to modernize and integrate our mainframe with contemporary platforms and tools. We’re seeking an experienced z/OS Systems Engineer with expertise in z/OS UNIX System Services (USS) and IBM zLinux (Linux on IBM Z) to drive innovation in bridging mainframe and distributed systems. In this role, you will:

Design and implement enhancements to our z/OS UNIX and zLinux environments – ensuring robust, secure, and scalable UNIX system services on z/OS and optimizing Linux on IBM Z for enterprise workloads. You will apply best-in-class engineering practices to develop new features, automate manual tasks, and improve the developer experience on the mainframe.

• Accelerate Modernization – Leverage modern interfaces like z/OS Management Facility (z/OSMF), the Zowe framework, and IBM Wazi to integrate mainframe systems into contemporary DevOps and cloud environments. This includes enabling REST APIs and CLI tools that allow distributed teams and modern applications to seamlessly interact with z/OS resources. You will play a key role in making the mainframe a more open and agile platform, bridging the gap between legacy systems and modern development practices.
• Implement DevOps and CI/CD practices for mainframe – Work on integrating z/OS with enterprise DevOps pipelines, enabling efficient use of mainframe capabilities in continuous integration and delivery processes. Introduce and support tools such as Git or Ansible for z/OS automation, and promote the adoption of modern mainframe development environments (e.g., using Zowe CLI and APIs for automation; exploring containerized dev/test frameworks like IBM Wazi for z/OS).
• Ensure system interoperability – Develop and maintain interfaces between z/OS and distributed (Linux/Unix) systems, enabling smooth data exchange and process integration. This may involve building secure API layers, cross-platform file sharing (e.g. via NFS or Zowe API Mediation Layer), and connecting mainframe services to cloud or hybrid environments.
• Operational Excellence – Integrate advanced observability and monitoring for USS and zLinux processes, using tools like system logs, SMF data, and modern monitoring dashboards (Grafana, Splunk, etc.) to ensure performance and reliability. You will also provide third-level support for complex UNIX and Linux-related issues on the mainframe, employing deep problem analysis to identify root causes and permanent fixes.
• Technical leadership – As a senior engineer, you will make high-impact decisions regarding our mainframe integration strategy. You’ll present solution designs and roadmaps to stakeholders and technical leadership, advocating for improvements that enhance agility and align with business needs. You will collaborate with architects and other senior engineers to design hybrid solutions that leverage mainframe strengths in a modern IT landscape. Furthermore, you will contribute to our culture by mentoring colleagues (e.g., in using new tools or approaches) and by sharing expertise in internal forums and guilds.

Your team: You’ll be part of the Mainframe Platform Core Services crew, working within a specialized zSoftware pod. This cross-functional team focuses on evolving the mainframe to support new interfaces and hybrid-cloud connectivity. You will closely partner with team members in Core z/OS Engineering, Middleware (CICS/MQ) Integration, Security, and Cloud Enablement to develop end-to-end solutions that connect mainframe services with modern platforms.

The team operates globally, so you’ll collaborate with colleagues across different regions and time zones, bringing together a variety of skills to modernize our mainframe environment. The working model is agile, emphasizing iterative improvements, quick feedback loops, and continuous learning as we adopt new technologies in the mainframe context.

Your expertise: You are a seasoned mainframe engineer (8–10+ years of experience) with a blend of traditional mainframe skills and modern tooling knowledge. Key qualifications include:

• z/OS UNIX System Services (USS) – Advanced knowledge of UNIX on z/OS (shell environment, POSIX interfaces, zFS file system management, Unix security model) and the ability to develop and debug programs or scripts running under USS. Experience porting or integrating open-source tools (e.g., Git, Python) onto USS is an advantage.
• Linux on IBM Z – In-depth understanding of zLinux (Linux running in KVM or LPAR on IBM Z hardware), including system installation, networking, and performance tuning in a mainframe environment. Familiarity with virtualization via KVM and concepts like IFL processors, CPU management, and resource sharing on IBM Z is expected.
• Modernization Tools – Hands-on experience with or strong knowledge of modern mainframe tools such as z/OSMF (IBM z/OS Management Facility) for web-based system management, Zowe (Open Mainframe Project’s framework for mainframe integration) — e.g., usage of Zowe CLI/Explorer and API mediation for connecting mainframe services with cloud – and IBM Wazi for cloud-based mainframe development/testing. Your ability to utilize these tools and frameworks is critical for enabling an API-driven, cloud-integrated mainframe environment.
• Systems Programming & Scripting – Proficiency in shell scripting, REXX, and programming languages like Python or C/C++ on z/OS or Linux, enabling you to create automation scripts, API endpoints, and system utilities bridging z/OS with distributed systems. Exposure to infrastructure-as-code (e.g., Ansible on z/OS) is a plus, emphasizing code-driven system management.
• Software Maintenance & Configuration – Solid knowledge of SMP/E, with proven experience in installing, configuring, and migrating new product versions.
• Networks & Security – Good grasp of mainframe networking (TCP/IP on z/OS) and cross-platform security protocols. Understanding how to manage secure APIs and connectivity between z/OS and external systems (e.g., leveraging encryption, RACF rules for cross-platform access, etc.) is important for safe integration.
• Performance & Reliability – Experience optimizing the performance of USS workloads and zLinux instances, including resource allocation, workload balancing, and monitoring of key metrics (like CPU, memory usage on IFLs, network throughput) to ensure stable operations. Familiarity with mainframe performance tools and logs (SMF, RMF) is expected.
• Strategic & Innovative Mindset – Passion for modernizing mainframe usage and staying updated on industry trends (for example, containerization on zLinux, cloud integration, DevOps practices for mainframe). Ability to evaluate emerging technologies and incorporate them into the mainframe environment when beneficial.
• Communication & Collaboration – Excellent English communication skills are essential, enabling you to collaborate effectively with global teams and to clearly present modernization plans to both technical and non-technical stakeholders. You are comfortable in a leadership capacity, coordinating initiatives across different groups, and nurturing a culture where mainframe and distributed teams collaborate seamlessly on hybrid solutions.

By joining our team as a senior mainframe engineer in any of these roles, you will be empowered to work independently, make critical technical decisions, and visibly shape the future of our mainframe platform in a dynamic, agile environment. You’ll leverage your deep specialty—be it base z/OS systems, workload automation, or mainframe Unix/Linux integration—to drive high-impact improvements that keep our mainframe systems robust, modern, and aligned with business needs.

We value proactive engineering leadership, strong communication, and a commitment to continuous learning and innovation across all these positions. Each role offers the opportunity to take ownership of technical solutions and present them to stakeholders and technology leadership, ensuring your contributions directly influence our organization’s success.